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Old 04-29-2018, 06:12 PM   #1
vince1
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Alternate carb for 66 250?

Last tank, although sitting over winter, was only 13 1/2 MPG imp (12 US). Are there any easy to install progressive 2V's out there worth trying? It seems as if she would like to run a little leaner on the lower RPM's.
Thanks.
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Old 04-29-2018, 07:07 PM   #2
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Re: Alternate carb for 66 250?

What rear gears you have? That will have the most influence on your MPG. What you are stating is about normal for the average truck with a 250 I6.
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Old 04-29-2018, 07:22 PM   #3
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Re: Alternate carb for 66 250?

have HEI?
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Old 04-29-2018, 08:08 PM   #4
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Re: Alternate carb for 66 250?

HEI with 3.07's. Starts and runs good but probably the original engine with 107k (or 207k?) miles. Compression is OK. Needs resealing.

Maybe it would do as well or better with a 350/350 combo and be a lot more fun to drive.
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Old 04-29-2018, 08:51 PM   #5
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Re: Alternate carb for 66 250?

maybe but what c10 out there doesnt have that comb? no offense to anyone that has that combo but it starts to become a repeat when everyone has the same combo at the car show/cruise.
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Old 04-30-2018, 12:30 AM   #6
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Re: Alternate carb for 66 250?

My '65 with a 230, 3 speed in the floor, 4.11 gears gets like 10. I dont really expect to get much better with the combo i have. lol
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Old 04-30-2018, 12:44 AM   #7
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Re: Alternate carb for 66 250?

My car show vehicle is a 64 Rambler LOL. The show today got rained out.

Wow, 411's is low. I was teaching my daughter to drive a standard when it had the 3.73's. She asks where's the next gear and I say that's it. She thought that was pretty funny.

I guess I'll keep the truck as is. Its not ready for shows yet but lots of people like looking at it. Yesterday it dragged around a float with 1/2 X 5 lag bolts to somewhat smooth out my not yet green lawn. This morning it took away an old hot water tank and five jugs of used oil. Wiper blade fell off half way to town. Now its got a fridge and futon frame on it to get rid of. Then probably back to retirement for a month or so. Lots of fun.

My thinking on a different carb is that it could improve the mileage a bit. I suppose though that it would not be so easy hooking up the linkage and oil bath air cleaner without a lot of modification.

Last edited by vince1; 04-30-2018 at 09:11 AM.
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Old 04-30-2018, 10:30 AM   #8
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Re: Alternate carb for 66 250?

I've got a 4 barrel Holley Economaster on my shelf that I picked up but never used on a previous 250. Supposedly they were made for better mpgs back in the gas crisis days, so I've been curious of what the actual results would be.
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Old 04-30-2018, 04:39 PM   #9
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Re: Alternate carb for 66 250?

I am guessing your carb could use a little work. I have a 1963 with the Rochester B, 230 inline 6, 3.73 gears, and I'm somewhere between 15 and 20 MPG on the highway.

I think the perfect fit for us with inline 6's is Holley's new two barrel throttle body injection set-ups. I will be moving to one in the near future.....once I find a decent fitting gas tank......

https://www.holley.com/products/fuel.../parts/550-849
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Old 04-30-2018, 04:50 PM   #10
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Re: Alternate carb for 66 250?

A two barrel Weber will be tuneable with jets readily available and there is a ton of info online about tuning them. You can lean out the idle jets (low speed/part throttle) to get better mileage. Get a wideband air/fuel ratio gauge so you can see exactly how lean/rich its running then tune from there.

I added two 36mm Dellorto two barrel carbs to an otherwise stock 1600cc engine in my '64 VW. I was getting 24 mpg mixed city/highway mileage with the stock 34mm single barrel. After going to the Dellorto's I couldn't make it get under 28.5 driving it hard around town, and it got a best of 35.25 highway mileage. I usually got 32 mixed when I wasn't trying to get better mileage. Having the right carburetion and timing can make a huge difference in mileage.
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Old 04-30-2018, 07:30 PM   #11
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Re: Alternate carb for 66 250?

With the nice weather here I'l try to find a day to wander around Pick n Pull to see if I can come up with an alternative for a better carburetor.

I'll also read up some on fuel injection but so far am pretty limited on knowing what to do. The fuel tank has been changed to the back though so step one done?
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Old 04-30-2018, 11:56 PM   #12
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Re: Alternate carb for 66 250?

Weber 32/36 is good progressive 2 barrel and the last guy I remember doing it got around 24 mpg. IF I am remembering right, but with lot's of tuning and patience he had that motor running perfect and getting awesome mileage. Seems I remember him having 3.07 gears as well.

http://www.langdonsstovebolt.com/sto...egory=18665963

Carb and adapter can be purchased here.

The 350/350 combo will Not get you better mileage without tons of money being spent anyhow. Will be more powerful for sure, but you could make decent power with the 250 if you wanted as well.
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Old 05-01-2018, 02:10 AM   #13
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Re: Alternate carb for 66 250?

I also was using a 32/36 Weber from Langdons stovebolt and it was a great carb. It did take some tuning but well worth it, engine ran better, way more efficient and had a little more jam than the old Rochester when the secondaries opened up.
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Old 05-01-2018, 07:21 AM   #14
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Re: Alternate carb for 66 250?

dracko what all did you do to make it work? Different manifold or modification?

I've got to weigh that versus getting a whole V-8/auto and maybe crossmember/brake setup from another truck.
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Old 05-01-2018, 10:39 AM   #15
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Re: Alternate carb for 66 250?

The swap is pretty straight forward and Tom is a good dude, always responds to questions pretty quick. He makes a manifold adaptor and pretty nice air cleaner setups for them. I had to make a new linkage with some 1/4” threaded rod.

The one complaint I had was the electric choke, I was driving the truck all winter at the time and couldn’t get the choke dialed in, always had to sit in the truck til warmed up feathering the pedal. It would open up too soon.

Drivetrain swap is a tough call. After tearing the truck down for “restoration” I sold the 230/granny 4 speed and have a rebuilt 327 and MY6 now. Prob should’ve just kept it the 6 because it was great around town. Just wanted OD.

Don’t regret the crossmember swap though, newer front end components and disc brakes are never a bad thing.
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Old 05-01-2018, 12:05 PM   #16
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Re: Alternate carb for 66 250?

About the Holley 4 barrel.

I had a 58 Ford Y block with the 2 barrel only getting 12 MPG.
A friend sold me a manifold with a broken lug and a vacuum secondary carb with shrunken gaskets. I brazed the lug back on the manifold in high school shop class and put a kit in the carb. Wow, I could get 20 MPG.

I don't think a 4 barrel goes well with a 6 cylinder though without a manifold change.

Thanks for all your replies. The path ahead looks much clearer.
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Old 05-01-2018, 02:08 PM   #17
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Re: Alternate carb for 66 250?

Another option may be an early 80s Escort carb. It's made by Weber and is very similar to the Weber progressive two barrel carbs but seems to be higher quality than the aftermarket Webers. They're very inexpensive on eBay, I bought one for my Festiva for $60 bucks. They take Weber jets so they're tuneable. It also has a vacuum operated idle-up feature if you're running A/C.

https://www.ebay.com/itm/New-Genuine...nd!29625!US!-1
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Old 05-01-2018, 03:59 PM   #18
vince1
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Re: Alternate carb for 66 250?

That was my thinking with cruising Pick n Pull. I know some Fords used 2 barrels with vacuum secondaries. Could be though that they may be getting scarce due to their age but worth taking a look. Would that EBay carb have enough CFM capability for the six cylinder?
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Old 05-01-2018, 04:23 PM   #19
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Re: Alternate carb for 66 250?

The one I used is from a 1.6 Escort making around 80 hp and has a mechanical secondary. I stuck one on my Festiva and it ran great out of the box from idle to almost 7k rpm.

I did find this on a site selling Weber carbs, same series as everyone uses on L6's. According to this they're only good for up to 2300cc so they usually would be undersized on a 250 (4.1L) but the sixes don't rev very high and the cylinder head doesn't flow well. The Escort carb is a near copy of the DGV carbs so I'd thing they'd perform similarly.


Quote:
THE DGV SERIES

Any search for the ideal 2-barrel, progressive down-draft carburetor would surely end with the DGV Series. look no further for versatility, wide adaptability, easy installation, low initial cost, trouble-free maintenance, excellent drivability, increased fuel economy and improved performance. Designed for engines displacing 1200cc-2300cc, the DGV Series carbs feature diaphragm type accelerator pump circuits and models with manual, water or electric choke actuation. The DGV also has a power valve circuit to facilitate low vacuum running conditions.

Greater improvements in throttle response at a slight penalty in fuel economy can be achieved by using the 38 DGAS synchronous opening model. This is a high performance alternative to most any DGV applications.
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Old 05-02-2018, 05:01 AM   #20
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Re: Alternate carb for 66 250?

here is the 250 i sold 5 years ago in how the carb should look like
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